Drafting system for textile fibers



Dec. 16, 1952 E. R. GOSHAWK 2,621,373

DRAFTING SYSTEM FOR TEXTILE FIBERS Filed Aug. 29, 1949 Attorney;

Patented Dec. 16, 1952 DRAFTING SYSTEM FOR TEXTILE FIBERS Eric R.Goshawk, Rock Bank, Bollington, England, 'assignor to Fine Spinners &Doublers Limited, Manchester, England Application August 29, 1949,Serial No. 112,917

, In Great Britain September 4, 1948 2 Claims.

This invention relates to improvements in drafting systems for textilefibres and particularly but not exclusively to high drafting systems Itis well-known in roller drafting devices that an eccentric top roller orbottom roller causes periodic thick and thin places in the draftedslivers, rovings or yarns. This is usually due to the movement of theroller-nip of one roller pair in relation to the roller-nip of thepreceding roller pair and since, in a drafting sequence, the highestdraft occurs in the front zone, it is on the fron roller pair thateccentricity should be eliminated as far as possible. Although perfectroller-nip control is desirable in all drafting heads it becomes moreessential to good work in ring spinning frames using high draft systems.The top rollers of a ring spinning frame are assembled in pairs and areeasily removable from the frame. Should any fault develop in abottom-roller line, however, it is impossible in most cases to correctit without removal from the frame and consequent loss of production.

The object of the present invention is the automatic correction of anymovement of the bottom-roller centre due to rotation, by the creation ofan equal and opposite movement of the centre of the top cushioned rollerin such a manner that the line of contact between the two remainssubstantially unchanged in position, such correction being hereinafterreferred to as nip stabilization.

The invention consists in means for obtaining nip stabilization betweentwo lines of drafting rollers wherein any movement of the front bottomroller axis during rotation creates an opposite movement of the axis ofrotation of the top roller so that the nip of the two rollers remains inthe same plane as that in which their axes were originally located.

The invention is illustrated in and will be described with reference tothe accompanying drawings, in which:

Fig. 1 is a geometrical diagram illustrating the principle of theinvention,

Fig. 2 is an end elevation of the top and bottom front rollers of a ringspinning frame, the position of the top roller being controlled from thebottom roller according to the invention,

Fig. 3 is a plan in half section on line :c-y of Fig. 2,

Fig. 4 is a front elevation of Fig. 2, and

Figs. 5 and 6 are detail perspective views of the parts of the devicecontrolling the top roller.

The principle of the device for nip stabilization is illustratedgeometrically in Fig. l where 2 B and T represent the bottom and topfront line drafting rollers of a ring spinning frame. The rollers arerespectively of radii r and r with centres C and C vertically aligned.

Suppose the centre of B moves to the point 7 C 1 and that at the sametime the centre of T moves to the point C 2 this point being such thatthe line C 1 C 2 is out by the line C C in the ratio r to r then thisintersection will be the new point of roller contact and as this pointof roller contact is still on the vertical line C C its relation totheroller-nip of a second line of rollers will remain unchanged: since themovement of the roller centres is at most only a few thousandths of aninch the slight vertical change in "the nip position as shown in Fig. 1is of a secondary order and of no practical significance.

In the arrangement shown in Figs. 2 to 5 for carrying the invention intopractical effect the cap-bar neb is formed in two parts N and Nseparated a short distance apart to permit of motion of the front memberW relative to the rear member N The rear member N carries the web wwhich forms a recess between the member N and the member N in which thespindle F of the roller T is journalled the member N being rigidlysecured to a stiff cap bar b.

A bracket B which extends forwardly over the front member N is securedto or formed integrally with the rear member N The front portion of thebracket B extends downwardly and its inner face is parallel to the planein which the axes of the two rollers T and B are located.

A rocker V is secured to or formed integrally with the front member N ofthe neb. In the face of the rocker V two shallow circular recesses U areformed and two similar recesses are formed on the inner face of thebracket B, these recesses serve to retain two compression springs 1!.which force a recess 1) in the rocker V against a pin 1) which passesthrough a hole in the end of a short rod J. This rod is threaded at theother end to receive a knurled adjusting nut n and passes through holesb 0 respectively in the bracket B and the rocker V allowing ampleclearance for slight oscillation of the latter about the pin p.

The bracket B is set so that the rocker V presses against the land b ofthe bottom fluted roller 13 and the nut 11. adjusted to bring the faceof the member N into correct position relative to the member N The toproller weighting must be such as to press the roller spindle F forwardagainst the front member as shown in Fig. 3.

When the roller B is rotating, any eccentric motion of the roller land bagainst the rocker V will cause the rocker to rock about the pin p withthe result that the face of the member N will be moved in the oppositedirection and this movement being imparted to the top roller spindle F,thereby maintaining automatically the desired nip stabilization.

It will be appreciated that the device as described can be applied onlyat roller lands situated between roller stands and is not applicable atthe roller neck where, in any event, it should be unnecessary.

I claim:

1. In a drafting system for textile fibres, the combination of a toproller having a spindle and a cooperating bottom roller having a landthereon, a cap bar, a cap bar neb for the spindle of the top rollerformed in two parts, a rear part affixed to the cap bar and a front partmovable in relation to the rear part, said rear and front parts beingspaced apart to receive the spindle of the top roller between them, andan extension of the front part mounted between its ends to rock in aplane transverse to the axes of the top and bottom rollers and carryingsaid front part at one end and which is engaged at its other end by theland on the bottom roller, and means acting on said extension to presssaid front part on one end thereof against the spindle of the top rollerand to press the other end of said extension against the land on thebottom roller, whereby any movement of the axis of the bottom roller istransmit:- ted by said extension and front part to the top roller in theopposite direction so that the nip of the two rollers remains in thesame plane as that in which their axes were originally located.

2. In a drafting system for textile fibres, the combination of a toproller having a spindle and a bottom roller having a land thereon, a capbar, a cap bar neb for the spindle of the top roller formed in twoparts, a rear part aflixed to the cap bar and a front part movable inrelation to the rear part, a bracket carried by the rear part andextending over the front part, a rocker plate atfixed to the front partand located behind the bracket, a fulcrum carried by the said bracketabout which the rocker plate can rock, springs arranged between thebracket and the rocker plate to press the front part of the cap bar nebagainst the spindle of the top roller and the lower part of the rockerplate against the land on the bottom roller whereby any movement of theaxis of rotation of the bottom roller creates an opposite movement ofthe axis of rotation of the top roller so that the nip of the tworollers remains in the same plane as that in which their axes wereoriginally located.

ERIC R. GOSHAWK.

No references cited.

